1. Field of the Invention
The present invention relates to a method for controlling root parasitic plants comprising regulating the activity of a protein associated with the strigolactone biosynthetic pathway (including the strigolactone biosynthetic and signalling pathway) or expression of a gene encoding such a protein.
2. Background Art
Damage to agricultural crops caused by root parasitic plants (or root parasitic weeds), such as Striga or Orobanche species, is a global-scale problem in recent years. In Africa, in particular, two-thirds of cereal growing areas are damaged by Striga (mainly Striga hermonthica), and such damage affects food supply to as many as 300 million people.
Root parasitic plants develop an organ that is referred to as the haustorium after germination and they grow by taking roots of host plants and depriving them of nutrients or moisture. Seed germination of root parasitic plants in the soil is induced by strigolactone, which is a germination stimulant released from the root of the host plant. This is considered to be deeply involved in the survival strategy of root parasitic plants, which experience selective germination of seeds distributed in the vicinity of the root of the host plant (i.e., a radical can reach the root of the host plant after germination).
Recently, strigolactone was demonstrated to be a substance that is essential for host recognition of symbiotic arbuscular mycorrhizal fungi (AM fungi). Specifically, root parasitic plants are considered to utilize strigolactone that a plant originally releases for AM fungi to search for the root of a host plant.
Establishment of an effective method for avoiding or controlling root parasitic plants is a highly important and urgent global-scale objective, although no effective method has yet been developed.